In a retail service station environment, customers use a fuel dispenser to pump fuel from an underground storage tank (UST) into their vehicle's fuel tank. Fuel flow meters are used by the fuel dispenser to measure the amount of fuel being dispensed. As fuel is dispensed, it flows through the flow meter, which generates an output signal proportional to the flow rate or volume of the fuel. The output signal, generally in the form of a pulse train, is received by the fuel dispenser control system, which calculates and displays the volume and price of fuel dispensed.
Fuel flow meters must be very accurate in order to ensure that customers are properly charged for the fuel that has been dispensed. Seasonal variations in fuel temperature can cause errors in flow meter output, thus requiring frequent meter testing and recalibration to ensure accuracy. Fuel flow meters must comply with regulatory requirements regarding measurement accuracy which are enforced by Weights & Measures (or an equivalent regulatory authority). Failure to comply with these regulatory requirements can result in an entire fueling station being temporarily shut down until the issues with the flow meters are rectified.